  .shell-container {
            position: fixed;
            left: 0;
            top: 0;
            height: 100vh;
            z-index: 1000;
        }

        .shell {
            width: 90px;
            height: 100%;
            background: var(--card-bg);
            display: flex;
            align-items: center;
            flex-direction: column;
            transition: width 0.3s ease;
            overflow: hidden;
            box-shadow: var(--shadow);
            border-radius: 0 16px 16px 0;
        }

        .shell:hover {
            width: 250px;
        }

        .shell__item {
            display: flex;
            align-items: center;
            width: 85%;
            padding: 16px 12px;
            margin: 8px 0;
            border-radius: 12px;
            transition: all 0.3s ease;
            color: var(--text-secondary);
            position: relative;
        }

        .shell__item:hover {
            background-color: rgba(74, 107, 255, 0.08);
            color: var(--primary-color);
        }

        .shell__item.active {
            background-color: rgba(74, 107, 255, 0.12);
            color: var(--primary-color);
        }

        .shell__icon {
            min-width: 28px;
            text-align: center;
            font-size: 22px;
            margin-right: 15px;
            transition: transform 0.2s;
        }

        .shell__item:hover .shell__icon {
            transform: scale(1.1);
        }

        .shell__title {
            font-size: 16px;
            font-weight: 500;
            opacity: 0;
            white-space: nowrap;
            transition: opacity 0.2s;
        }

        .shell:hover .shell__title {
            opacity: 1;
        }

        .logo {
            padding: 25px 0;
            margin-bottom: 15px;
            display: flex;
            align-items: center;
            justify-content: center;
            width: 100%;
        }

        .logo img {
            width: 42px;
            height: 42px;
        }

        .logo-text {
            font-size: 20px;
            font-weight: 700;
            color: var(--primary-color);
            margin-left: 12px;
            opacity: 0;
            transition: opacity 0.3s;
            white-space: nowrap;
        }

        .shell:hover .logo-text {
            opacity: 1;
        }